Search

The present work illustrates the synthesis and electrochemical performance of rGO-TiO2 composite electrodes for their potential application in energy storage devices. The rGO-TiO2 composite was prepared via ultrasonication method, and rGO-TiO2 electrodes were prepared by drop-cast technique. The rGO-TiO2 composite electrodes were electrochemically analyzed using galvanostatic charge–discharge (GCD) and cyclic voltammetry (CV) methods. These tests were performed with three distinct electrolytes (H2SO4, Na2SO4, and KOH), each with a 1 molar concentration. The rGO-TiO2 composite electrodes' specific capacitance (Csp) in 1 M H2SO4 electrolyte was estimated to be 4.89 F/g; it was estimated to be 3.35 F/g in case of 1 M Na2SO4 and 1.42 F/g for the 1 M KOH liquid electrolyte at a scan rate of 0.05 V/s. Using GCD, it was found that in the case of 1 M H2SO4, energy density and power density values were 1.78 Wh/kg and 4000 Wh/kg at a current density of 10 A/g, respectively; in 1 M Na2SO4, the energy density was found to be 2.58 Wh/kg, and conversely, in 1 M KOH, the energy density was measured as 2.39 Wh/kg at 1.25 A/g. AC impedance studies were conducted, and the prepared rGO-TiO2 electrodes exhibited specific capacitance values of 14.21 F/g, 12.68 F/g, and 15.02 F/g in H2SO4, Na2SO4, and KOH electrolytes, respectively. Hence, the research work demonstrated a simple and affordable method of synthesis of rGO-TiO2 electrodes that holds promise for supercapacitor applications, particularly when optimized for specific electrolyte conditions. [ABSTRACT FROM AUTHOR]

This study aims to enhance the multiferroic properties of bismuth ferrite (BFO) by investigating the effects of substitution with erbium (Er) on the material's structural, optical, and magnetic characteristics. Er-substituted bismuth ferrite (Bi1−xErxFeO3) (x = 0, 0.04, 0.08, 0.12, 0.16) nanoparticles (NPs) were synthesized via the very cost-effective Pechini modified sol–gel method followed by auto-combustion. X-ray diffraction (XRD) patterns confirmed the crystallinity, structure, and purity of the phase, revealing the formation of single-phase materials. The bond structure of the prepared samples was examined using Fourier transform infrared (FTIR) spectroscopy, confirming the significant stretching and bending of bonds of perovskites. Electron paramagnetic resonance (EPR) findings suggested a broadening of the signal as well as a shift of the center of resonance to lower fields. The experimental findings revealed that Er doping has a significant effect on the magnetic ordering and saturation magnetization of BiFeO3. In addition, UV–Vis spectroscopy demonstrated that the energy bandgap in the prepared samples varies from 2.13 eV to 1.71 eV. This research contributes to an understanding of the enhanced structural, magnetic, and optical properties of Er-substituted BFO nanoparticles, which is useful for designing and developing multiferroic materials with enhanced magnetic functionality for next-generation magnetoelectric devices, optoelectronic devices, and photocatalysts. [ABSTRACT FROM AUTHOR]

Magnesium-doped nickel ferrite nanoparticles with the chemical composition (Ni1−xMgxFe2O4, x = 0.00, 0.20, and 0.40) have been prepared by a modified sol–gel citrate method. Structural analysis was carried out through x-ray diffractograms (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The spherical-shaped morphology of the prepared nanoparticles has been confirmed by field-emission scanning electron microscopy (FESEM). The energy dispersive x-ray (EDX) analysis confirmed the presence of elements (Ni, Mg, Fe, and O) in the prepared compositions. The distribution of cations over tetrahedral and octahedral sites has been confirmed by Rietveld refinement using FullProf software. The phenomena of Maxwell–Wagner polarization is exhibited in the dielectric measurements. Cole–Cole plots showed that the net grain (Rg) and grain boundary resistance (Rgb) values are decreasing for the maximum concentration of Mg2+ ions in the nickel ferrites. Almost 96% deductions in the tangent loss values have been observed at high temperatures with the increasing concentration of Mg2+ ions in the nickel ferrites. Fitting of AC conductivity was carried out using the Jonscher Power Law function. The net magnetization saturation values also decreased from 27.7 emu/g to 16.7 emu/g upon the doping of Mg2+ ions in the pure nickel ferrites. These properties are all desired for materials working under high-frequency applications. [ABSTRACT FROM AUTHOR]

This research addresses the scalable and inexpensive synthesis of α-Fe 2 O 3 via hydrothermal method without any precipitating agent as well as the enhancement of solar driven photocatalytic and H 2 production through doping different chromium proportions. Competency of α-Fe 2 O 3 , both pure and doped with chromium, to function as photocatalyst was evaluated by its interaction with multiple dyes, which was real-time monitored utilizing (Internet of Things) IoT technique. By adding chromium, the rate of deterioration increased substantially from 15 to 94% for TB under sunlight in a remarkably brief 20 min by employing a very small amount of Cr 0.8 Fe 1.2 O 3 (0.3 g/L), as evidenced by high degree of mineralization i.e. 85% and LC-HRMS. Also, the rapid breakdown of Trypan Blue (TB) was indicated by BOD 5 /COD ratio. Moreover, Cr-doped α-Fe 2 O 3 displays excellent H 2 production (~ 132 μmol h -1  g -1 ) as compared to α-Fe 2 O 3 . This work highlights the potential utilization of Cr-doped α-Fe 2 O 3 for the purification of industrial waste water and green energy harvesting., (© 2024. The Author(s).)